Interpretive Summary: Switchgrass is considered a potential commercial biomass feedstock but field scale production and production cost data have been limited. Here we report, as a benchmark, the actual costs of production incurred on ten commercial-sized fields in the northern Great Plains, between 2000 and 2005. Ten cooperating farmers grew the crop for five years each on fields ranging from 7.5 to 24 acres. A total of 173 acres were planted, 10 acres of which were abandoned because of poor establishment due to drought. Total five-years expenditures on these 173 acres were $60,850, plus land rent totaling $49,900. Total production was 2,232 ton (US) of air-dry switchgrass, for an average yield over the four full production years of 3.4 tons per acre per year. The overall average cost of production was about $27 per ton plus $23 per ton for land rent. If establishment costs were pro-rated over a more typical nine production years rather than four, total production costs would fall by 12%. Yields through the five years averaged 0.4 ton per acre for the establishment year, then 2.1, 3.1, 4.2 and 3.5 ton per acre. Total costs for individual farms, ranged from $29 to $110 per ton of biomass. The potential for reducing establishment costs and increasing yields suggests that substantial quantities of switchgrass would be produced in just a few years with prices as low as $36-$40 per ton at the farm gate. At a conversion rate of 80 gallons of ethanol per ton, the biomass feedstock cost at the farm gate would be about $0.50 per gallon.

Technical Abstract:
Switchgrass is considered a potential commercial biomass feedstock but field scale production and production cost data have been limited. Here we report, as a benchmark, the actual costs of production incurred on ten commercial-sized fields in the northern Great Plains, between 2000 and 2005. Ten cooperating farmers grew the crop for five years each on fields ranging from 3 to 10 ha. A total of 70 ha were planted, 4 ha of which were abandoned because of poor establishment due to drought. Total five-year expenditures on these 70 ha were $60,850, plus land rent totaling $49,900. Total production was 2,026 Mg of air-dry switchgrass, for an average yield over the four full production years of 7.6 Mg/ha/year. The overall average cost of production was about $30/Mg plus $25/Mg for land rent. If establishment costs were pro-rated over a more typical nine production years rather than four, total production costs would fall by 12%. Yields through the five years averaged 0.9 Mg/ha for the establishment year, then 4.9, 7.0, 9.4 and 7.9 Mg/ha. Total costs for individual farms, ranged from $32 to $121/Mg. The potential for reducing establishment costs and increasing yields suggests that substantial quantities of switchgrass would be produced in just a few years with prices as low as $40-$45/Mg at the farm gate.